The quota is "whenever CloudFlare decides I've used too much of their caching", I think. Hetzner is pretty great about bandwidth, I think they'll let me use as much as will saturate the connection to the DC.
I was but I'd forgotten, thanks for reminding me! Also, Cloudflare now have a very nice image resizing product which I'd probably use if IMGZ didn't need to resize ten images per year.
I'm not sure they're ready for my kind of volume yet.
https://news.ycombinator.com/item?id=20791660
E: lol you were in that thread, you probably know about it